Chemische Konstitution und Wirkung sulfonsäuregruppenhaltiger Mottenschutzmittel

Abstract

1. The commercially available, strongly effective sulfonated preparations used to control keratinovorous insect larvae comprise, besides a sulfonic acid group, three halogen substituted benzene nuclei.
2. The following molecular configuration is characteristic for [formula] the products Mitin FF manufactured by J.R. Geigy AG, and Eulan CN and Eulan FL manufactured by Farbenfabriken Bayer AG, whereas X may be of different structure. The position of the third benzene nucleus in Mitin FF and in the Eulan products is not identical. 
3. The above basic configuration is also characteristic for many other moth controlling agents.
4. Monosulfonic acids as a rule are more effective than disulfonic acids.
5. A central position of the sulfonic acid group in the total molecule, if possible in ortho position to another substituent (which may be weakly basic), normally favours the toxicity of a product. The benzene nucleus carrying the sulfonic acid group is advantageously halogenated.
6. In most cases the direct introduction of a sulfonic acid group in the benzene nucleus (after-sulfonation) in order to render soluble a product which is difficultly soluble or insoluble in water, strongly impairs its effect. More suitable is the solubilisation in water by acylation with the sulfobenzene carboxy lie acid.
7. The commercially available sulfonated moth proofing agents contain at least four nuclearly bonded chlorine atoms; the most preferred position of the chlorine atoms with respect to an existing substituent are the 4-, 3,4- or 2,4-positions. However, the presence of nuclearly bonded chlorine atoms is not in ail cases an evidence for the presence of a moth-proofing effect.
8. In directly comparable molecules one or two chlorine atoms may be advantageously replaced by a nuclearly bonded trifluoromethyl group.
9. Acid amide containing halogenated or trifluoromethylated monosulfonic acids of the aromatic series, especially carbamic acid amide containing monosulfonic acids, show strongest toxicity against moth larvae, as well as against larvae of attagenus and anthrenus.
10. Only a well balanced mutual accordancy of the different substituents (Cl, CF₃, OH, SO₃H) affords the highest biological effect of a molecule and a slight variation of the position of a substituent may substantially reduce the effect of the compound.
11. At this time the biological effect of a product cannot be predicted with certainly merely on the ground of the structural formular, notwithstanding certain structural characteristics which are common to effective products. At this time we also are unable to state on which factors the mutual influence of the substituents in a molecule in connection with the biological effect of the whole molecule eventually depends.
12. As regards the mechanism of the toxicity of the individual preparations there is little knowledge; the behaviour of the individual preparations as regards their toxicity against the larvae of moths, attagenus piceus and anthrenus vorax being often different.